Coloring StringGrid from database
lazarus / 10-Designer

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Stygian · 2016-09-01 11:41

Hello,

I'm looking for a method to color a stringgrid from database.
Everytime when a user set a color it will be saved into the database
and next time he/she start the application the coloring also loaded.

I cannot load the database into an array. It will be more than 10k
rows. Now it's small but it's growing day by day.

Thanks,
Sty

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balazsszekely · 2016-09-01 11:52

Is there any reason not to use a TDBGrid? Anyway you have the
OnDrawCell event for coloring. Just use the forum search, I'm sure
somebody already implemented a similar functionality.

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wp · 2016-09-01 11:54

Use the OnPrepareCanvas event of the DBGrid (I assume that you are
talking of a DBGrid, not of a StringGrid - but with the StringGrid the
solution would follow the same idea). Set the Brush.Color of the
canvas according to the value of the db field:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.DBGrid1PrepareCanvas(Sender: TObject; DataCol: Integer; Column:
TColumn; AState: TGridDrawState);begin  field: TField;  grid:
TDBGrid;begin  if (Sender is TDBGrid) then begin    grid :=
TDBGrid(Sender);    field :=
grid.Datasource.Dataset.FieldByName('the_name_of_the_color_field');  
grid.Canvas.Brush.Color := field.AsInteger;    // you may also have to
adjust the text color (black text on black doesn't look good ;-)    if
field.AsInteger > 3*128 then   // bright background --> black text   
 grid.Canvas.Font.Color := clBlack    else                           
 // dark background --> white text      grid.Canvas.Font.Color :=
clWhite;  end;end;

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Stygian · 2016-09-01 12:36

May i ask when PrepareCanvas execute? After each induvidual rowcount
incrase?

QuoteIs there any reason not to use a TDBGrid?I'm using a TTimer which
refresh an andon screen from the same database in every 5 sec. And i
cannot find an option for Manual Refresh in DBGrind.

Regards,
Sty

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balazsszekely · 2016-09-01 12:49

Quote@Stygian
I'm using a TTimer which refresh an andon screen from the same
database in every 5 sec. And i cannot find an option for Manual
Refresh in DBGrind.
Just refresh/reopen the dataset(Query, Table, etc...)

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wp · 2016-09-01 13:45

Quote from: Stygian on September 01, 2016, 02:36:36 pmMay i ask when
PrepareCanvas execute? After each induvidual rowcount incrase?
Whenever the grid is repainted. I don't know if the increase of
RowCount triggers a repaint of the grid, just call DBGrid1.Invalidate
if it does not.

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Stygian · 2016-09-05 13:15

Dear Everyone,

I dumped the my Stringgrid and changed everything on DBGrid. Now it's
working fine.

Thanks everyone for the help,
Sty